Capacitive effects of nitrogen doping on cellulose-derived carbon nanofibers

Carbons with valuable electrochemical characteristics are among the most convenient electrode materials used for energy storage. At the moment, their production is mostly reliant on unsustainable fossil fuels. A preferential sustainable production of enhanced carbonaceous electrodes can be achieved with more extensive utilization of abundant renewable resources instead of fossils. In this study; nitrogen-doped carbon nanofibers (CNFs) were synthesized from cellulose, the most abundant renewable resource, via consecutive steps of cellulose acetate electrospinning, subsequent deacetylation to cellulose, impregnation with nitrogen-containing additive (ammonium chloride), and carbonization. Results of material characterization showed that the carbonization of functionalized cellulose samples led to formation of CNFs doped with 4-5.6 at.% of nitrogen. In comparison with pristine CNFs N-doped samples had a slightly lower specific surface area, but higher conductivity and hydrophilicity. Moreover, electrochemical measurements indicated that the enhanced N-doped materials had about 2.5 times higher specific capacitance which was increasing throughout 1000 charge discharge cycles. These results suggest that nitrogen doping method used in this study has a positive pseudocapacitive effect on the electrochemical performance of carbonized cellulose materials. (C) 2015 Published by Elsevier B.V.